What is the fast way to remove ALL rows in DataGridView

I've a datagridview, whenever I display the master record, the associated children records are displayed in the datagridview. Bbefore filling in the children records into the datagridview again, I'll first clear all rows in the datagridview.

I first tried using the following statement and it did not work. I got an error msg: "Index out of range." Mus be non-negative and less than the size of the collection. There are 3 rows of data plus a blank row (at the bottom); hence Me.dgvMaterial_Inventory.Rows.Count = 4.

Me.dgvMaterial_Inventory.Rows.RemoveAt(dgvMaterial_Inventory.SelectedRows(dgvMaterial_Inventory.Rows .Count - 1).Index)

I then tried one row at a time using a For-loop as shown below
However, I got another error indicating "Uncommitted new row cannot be deleted." when trying to delete the 2nd row (with i=1).

Can someone please tell me why ? If this is not the correct way to do it, can you please advise what is the easy way to delete ALL rows.

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VB Code
Private Sub Clear_DataGridView()
Dim i As Integer

For i = 0 To Me.dgvMaterial_Inventory.Rows.Count - 1
Me.dgvMaterial_Inventory.Rows(i).Selected = True
Me.dgvMaterial_Inventory.Rows(i).Dispose()
Me.dgvMaterial_Inventory.Rows.RemoveAt(Me.dgvMaterial_Inventory.SelectedRows(0).Index)
Next
End Sub

dgvMaterial_Inventory.Clear ..... seriously, it's that easy. I think.

-tg

Not quite:

VB Code:

dgvMaterial_Inventory.Rows.Clear()

Having said that, if your grid is bound to a DataTable or some other DataSource then you need to clear it, not the grid.

I tried that but it didn't work. I got an error ("Cannot clear this List")
HElp me Thanks

Quote:

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Originally Posted by hoobas20

I tried that but it didn't work. I got an error ("Cannot clear this List")
HElp me Thanks

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Then your grid must be bound, which I've already addressed. If the grid is bound to a DataTable, which is the most common, then you either need to Clear the Rows collection of the DataTable itself or else unbind it by setting the DataSource to Nothing. Which is better depends on your situation.

Quote:

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Originally Posted by Ajax36

I've a datagridview, whenever I display the master record, the associated children records are
---------------
VB Code
Private Sub Clear_DataGridView()
Dim i As Integer

For i = 0 To Me.dgvMaterial_Inventory.Rows.Count - 1
Me.dgvMaterial_Inventory.Rows(i).Selected = True
Me.dgvMaterial_Inventory.Rows(i).Dispose()
Me.dgvMaterial_Inventory.Rows.RemoveAt(Me.dgvMaterial_Inventory.SelectedRows(0).Index)
Next
End Sub

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Hi. thanks for that code. I'm not good in english.

that code helped me but in this form:

Private Sub Clear_DataGridView()
Dim i As Integer

For i = 0 To Me.dgvMaterial_Inventory.Rows.Count - 1
Me.dgvMaterial_Inventory.Rows(0).Selected = True
Me.dgvMaterial_Inventory.Rows(0).Dispose()
Me.dgvMaterial_Inventory.Rows.RemoveAt(Me.dgvMaterial_Inventory.SelectedRows(0).Index)
Next
End Sub


I just replaced the "i" value with "0". Because every time you remove a row total rows value will be reduced.
So all the things you need is that each time you just need to remove the first row.

Sorry for my bad English writing.

Quote:

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Originally Posted by jmcilhinney

Not quite:

VB Code:

dgvMaterial_Inventory.Rows.Clear()

Having said that, if your grid is bound to a DataTable or some other DataSource then you need to clear it, not the grid.

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I have pretty much the same problem....slightly different. My grid leaves one empty row and I need that one gone as well. I suspect it's because the cursor is sitting in the bottom row, which of course is empty, at the time I clear the grid.

How do I get rid of that empty row. I tried .remove but I can't figure out what to add to .remove to do it..

Code:

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Me.DGV1.DataSource = Nothing
        Me.DGV1.Rows.Clear()

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Quote:

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Originally Posted by larrycav

I have pretty much the same problem....slightly different. My grid leaves one empty row and I need that one gone as well. I suspect it's because the cursor is sitting in the bottom row, which of course is empty, at the time I clear the grid.

How do I get rid of that empty row. I tried .remove but I can't figure out what to add to .remove to do it..

Code:

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Me.DGV1.DataSource = Nothing
        Me.DGV1.Rows.Clear()

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If you're talking about the new record row at the bottom then that is controlled by the AllowUserToAddNewRows property. It would be a rare thing to want to change at run time though. Why do you think you need to?

The reason I want to get rid of that row is because of my SAVE button code. I hand potential user errors in the data saving process with this code. This is the section dealing with the DGV. What it doesn't handle is a situation where the user may decide to clear the grid and for God only knows why....then hit the save button, which I do not want them doing if the grid is empty....but you just know someone will do that very thing...

Code:

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If DGV1.RowCount < (1) And TBoxFlowTestsCustID.Text < 1 Then
            MessageBox.Show("No Captured Flow Data To Save & Customer Data Is Incomplete", _
                            "C&D Data Archive Process", _
                            MessageBoxButtons.OK, MessageBoxIcon.None)
            Exit Sub

        End If

        If DGV1.RowCount < (1) Then
            MessageBox.Show("No Captured Flow Data To Save", _
                            "C&D Data Archive Process", _
                            MessageBoxButtons.OK, MessageBoxIcon.None)
            Exit Sub
        End If

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And it's within reason that they may want to save data with only 1 row in the DGV....so that's why its <1

allowuserstoaddrows = false took care of the problem....thank you for that.

Quote:

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Originally Posted by larrycav

The reason I want to get rid of that row is because of my SAVE button code. I hand potential user errors in the data saving process with this code. This is the section dealing with the DGV. What it doesn't handle is a situation where the user may decide to clear the grid and for God only knows why....then hit the save button, which I do not want them doing if the grid is empty....but you just know someone will do that very thing...

Code:

---

If DGV1.RowCount < (1) And TBoxFlowTestsCustID.Text < 1 Then
            MessageBox.Show("No Captured Flow Data To Save & Customer Data Is Incomplete", _
                            "C&D Data Archive Process", _
                            MessageBoxButtons.OK, MessageBoxIcon.None)
            Exit Sub

        End If

        If DGV1.RowCount < (1) Then
            MessageBox.Show("No Captured Flow Data To Save", _
                            "C&D Data Archive Process", _
                            MessageBoxButtons.OK, MessageBoxIcon.None)
            Exit Sub
        End If

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And it's within reason that they may want to save data with only 1 row in the DGV....so that's why its <1

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Removing the data entry row seems misguided to me. For one thing, you could just bind the grid and then use the data source to determine whether there is data to save. Even if the grid isn't bound, you can simply test for the presence of rows where IsNewRow is False.

Quote:

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Originally Posted by jmcilhinney

Removing the data entry row seems misguided to me. For one thing, you could just bind the grid and then use the data source to determine whether there is data to save. Even if the grid isn't bound, you can simply test for the presence of rows where IsNewRow is False.

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I trust your judgement but answer me this.... If the grid is cleared and that empty row remains, then wouldn't I code to look for IsNewRow = True....rather than false? I mean because the row is there...and I assume it's considered a new row...thus "true".

Quote:

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Originally Posted by larrycav

I trust your judgement but answer me this.... If the grid is cleared and that empty row remains, then wouldn't I code to look for IsNewRow = True....rather than false? I mean because the row is there...and I assume it's considered a new row...thus "true".

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No, because that row is always there, whether the grid is otherwise empty or not. IsNewRow is a property of each row, so you would look for the existence of at least one row where IsNewRow is False.

vb.net Code:

If myDataGridView.Rows.Cast(Of DataGridViewRow)().Any(Function(row) Not row.IsNewRow) Then
    'There is at least one row other than the new entry row in the grid.
Else
    'The new entry row is the only row in the grid.
End If

Quote:

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Originally Posted by jmcilhinney

No, because that row is always there, whether the grid is otherwise empty or not. IsNewRow is a property of each row, so you would look for the existence of at least one row where IsNewRow is False.

vb.net Code:

If myDataGridView.Rows.Cast(Of DataGridViewRow)().Any(Function(row) Not row.IsNewRow) Then
    'There is at least one row other than the new entry row in the grid.
Else
    'The new entry row is the only row in the grid.
End If

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Ok...will give that a whirl and see what happens.

But I'm not crystal clear on how the DGV behaves. When you say that row is always there, based on my setting the allowuserstoaddnewrows = false and as a result, my original code works as I expected.... THEN... when you say that row is always there, that is with the assumption that allowuserstoaddnewrows = true. .......Correct?

Just trying to grasp how .net works because it's not at all intuitive to me..yet.

Quote:

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Originally Posted by larrycav

Ok...will give that a whirl and see what happens.

But I'm not crystal clear on how the DGV behaves. When you say that row is always there, based on my setting the allowuserstoaddnewrows = false and as a result, my original code works as I expected.... THEN... when you say that row is always there, that is with the assumption that allowuserstoaddnewrows = true. .......Correct?

Just trying to grasp how .net works because it's not at all intuitive to me..yet.

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That is correct. What I'm saying is that you shouldn't be changing that property value just so that you can test for there being no rows in code.

Quote:

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Originally Posted by jmcilhinney

That is correct. What I'm saying is that you shouldn't be changing that property value just so that you can test for there being no rows in code.

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Very good...that's what I thought. Just wanted to verify what I thought I learned here was in fact correct. Thank you.